Scarlets v Ulster Parc y Scarlets, 7.35pm – Live BBC Two
A victory without the services of Charles Piutau and Ruan Pienaar would instantly steady Ulster's shaky campaign.
The problem is that Scarlets are all but done with European affairs, lying third behind tournament heavyweights, Saracens and Toulon, with two rounds to play.
Pienaar underwent knee surgery on Thursday and will be unavailable at least until Ulster’s Pro 12 fixture against Edinburgh on February 10th.
The Springbok scrumhalf is certain to miss three matches, including the Pro 12 visit to Llanelli Scarlets followed by round five and six of the Champions Cup away to Exeter and at home to Bordeaux Begles.
Pienaar sustained the injury to his right knee playing outhalf against Leinster on New Year's Eve.
It’s another tough blow for Les Kiss’s squad, providing an insight into what life will be like when the 32-year-old is forced to leave Belfast this summer, after the IRFU refused to green light a new contract.
This fixture has an eight even 10-point swing as the Scarlets coach Wayne Pivac noted: “If you look at the points table – ourselves, Glasgow and Ulster are probably at the moment fighting it out for the fourth position, unless there’s a change in form. It’s a massive game in the context of that push for top four, both teams will want a result from this one definitely.
“Our next two games in the Pro 12 are Ulster and Glasgow, teams sitting in fourth, fifth and sixth all within a couple of points of each other.”
Ulster are currently sixth in this three-way struggle to salvage the fourth and final Pro 12 play-off place. There is plenty of rugby to be played but, considering the road ahead, Kiss needs to alter a desperate five from eight losing streak away from Belfast.
They also need to close a four point gap between themselves, Glasgow and Llanelli.
With Piennar injured, and Piutau seemingly rested, Kiss must again turn to Paul Marshall to guide them from scrumhalf but at least the return of Paddy Jackson, along with Rory Best and Iain Henderson, promises an immediate improvement from the first-half collapse last weekend in Dublin.
Former Belvedere College schoolboy Dave Shanahan understudies for Marshall.
Tommy Bowe cannot get into the starting line-up as Andrew Trimble captains the side from right wing with Jacob Stockdale on the left while Luke Marshall and Stuart McCloskey are quietly cementing their midfield partnership in the injury enforced absence of Jared Payne and Stuart Olding.
But it is up front that Ulster must sort out these Scarlets. Best and Henderson at the coalface makes the fire in any Ulster pack hard to quell.
After Stephen Ferris questioned their heart and passion at half-time in the RDS, when they trailed Leinster 17-0, the inspiration must come now.
Logic and rationale points to Scarlets adding further misery to Ulster’s season. To win away without Piutau and Pienaar seems like too great a task.
SCARLETS: Johnny McNicholl, Liam Williams, Jonathan Davies, Hadleigh Parkes, Steff Evans; Dan Jones, Gareth Davies; Rob Evans, Ken Owens (capt), Werner Kruger; Jake Ball, Tom Price; Lewis Rawlins, James Davies, John Barclay. Replacements: Ryan Elias, Wyn Jones, Nicky Thomas, Joshua Macleod, Will Boyde, Aled Davies, Aled Thomas, Steff Hughes.
ULSTER: Louis Ludik; Andrew Trimble (capt), Luke Marshall, Stuart McCloskey, Jacob Stockdale; Paddy Jackson, Paul Marshall; Callum Black, Rory Best, Ross Kane; Kieran Treadwell, Iain Henderson; C Ross, C Henry, S Reidy. Replacements: J Andrew, A Warwick, J Simpson, F van der Merwe, P Browne, D Shanahan, B Herron, T Bowe.
Referee: Marius Mitrea (Italy).
Betting: Scarlets 10/11 with -4 handicap.
Forecast: Scarlets win.